Most of these books are valuable up to a point. The trouble is that few of the authors make an effort to view the big picture. It is easy for well-intentioned readers to view any book on wrongful convictions as sensationalistic by nature, and probably an aberration.

Five years ago, in an effort to bring the big picture into better focus, I led a national study of prosecutors involving journalists, lawyers, professors, database experts, and librarians. Our team examined more than 12,000 appellate court opinions going back to 1970 in which the defense alleged improper behavior by prosecutors. We discovered that wrongful convictions involving all kinds of crimes occur in many, many of the 2,341 US jurisdictions served by local district attorneys. (The nonpartisan Center for Public Integrity in Washington, D.C., published our findings under the title "Harmful Error.")

Twenty years ago, somebody raped and murdered 9-year-old Dawn Hamilton in Baltimore County, Md. Police received tips about the murderer, who had allegedly been hanging around an apartment complex where Dawn lived. Eventually, detectives worked from a composite heavily dependent on conflicting eyewitness descriptions provided by a 7-year-old boy and his 10-year-old buddy.

Detectives had no reason to suspect Kirk Bloodsworth. He was in his early 20s with no criminal record. He came from a solid family background. He had moved to the Baltimore area recently mostly because of his marriage. But the marriage was falling apart, and he had begun using drugs. He came to the attention of police only because he had left his wife after numerous arguments and she had retaliated by filing a missing person's report suggesting abandonment.

When Baltimore area police started hearing that Bloodsworth somewhat resembled the composite drawing and possessed personality traits that might be consistent with a profile based on FBI suppositions, detectives tracked him down. During questioning, Bloodsworth explained himself poorly, making statements that detectives misinterpreted.

But still, he should have been a free man after each of his jury trials. Prosecutors failed to turn over evidence that might have changed the outcome of the first jury's deliberations. The police ignored obvious suspects. The eyewitness accounts were contradictory and tainted.

Bloodsworth won his freedom from prison in 1993 only because of his persistence, his parents' willingness to live in poverty so they could finance his appeals, the advances in DNA testing, and lawyers who truly cared.

The Bloodsworth case has been chronicled extensively before, but this book, by lawyer-novelist Tim Junkin, is the most extensive treatment yet. Told mostly through the perspectives of Bloodsworth and his various lawyers, the book explains everything that went wrong to place an innocent man on death row for a crime he knew nothing about.

The prosecutors cared so little about justice in the Bloodsworth case that, after his exoneration, they did almost nothing to locate the real murderer until Bloodsworth pushed them to act. Finally, law enforcement agents analyzed a DNA sample, which led them to the real killer, who had struck again after Dawn Hamilton's death.

Reforms already instituted in some jurisdictions, notably in Illinois, can help avoid mistakes like this. Photo arrays and lineups conducted properly can minimize mistaken eyewitness identifications. Interrogations videotaped from start to finish can minimize false confessions. Complete disclosure of potentially exculpatory evidence by prosecutors can lead to the best possible representation for the accused. The most important safeguard, though, is police refraining from a rush to judgment.

The wrongful conviction problem is difficult to avoid, but not unsolvable, as this harrowing story shows.